Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 47. Charles Lutwidge Dodgson is perhaps not a name that is universally recognized, but Dodgson did achieve enormous success under the pseudonym Lewis Carroll. He created this pseudonym from the Latinization, Carolus Ludovicus, of his real given name. It was under the name Lewis Carroll that Dodgson published the children's books Alice's ...

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 47.

Charles Lutwidge Dodgson is perhaps not a name that is universally recognized, but Dodgson did achieve enormous success under the pseudonym Lewis Carroll. He created this pseudonym from the Latinization, Carolus Ludovicus, of his real given name. It was under the name Lewis Carroll that Dodgson published the children's books Alice's Adventures in Wonderland (1865) and its sequel Through the Looking Glass (1872). Though Dodgson achieved this success in children's literature, he was not an author of children's books by training or profession. His education and chosen field of pursuit were far removed from the field of children's literature and were instead focused on theoretical mathematics.

Dodgson graduated with honors from Christ Church, Oxford, in 1854 and then embarked on a career in the world of academia. He worked as a lecturer in mathematics at Oxford and, later in his career, published a number of theoretical works on mathematics under his own name rather than under the pseudonym that he used for his children's stories. He produced a number of texts for students, such as A Syllabus of Plane Algebraical Geometry (1860), Formulae of Plane Trigonometry (1861), which was notable for the creativity of the symbols that he used to express trigonometric functions such as sine and cosine, and A Guide for the Mathematical Student (1866). In a number of more esoteric works, he championed the principles of Euclid; in Euclid and his Modern Rivals (1879), he presented his ideas on the superiority of Euclid over rival mathematicians in a highly imaginative fashion, by devising, a courtroom trial of anti-Euclid mathematicians that he named "Euclid-wreakers" and ultimately finding the defendants guilty as charged. Curiosa Mathematica (1888-1893) made a further defense of Euclid's work, focusing on Euclid's definition of parallel lines. These academic works never had the universal impact of Dodgson's works for children using the name Lewis Carroll, but they demonstrate a solid body of well-regarded academic material

The word "they" in paragraph 2 refers to ______.