C. neck

(In the word "neck", the underlined part "e" has a different sound /ɛ/ compared to the other words, which have the /ɪ/ sound.)

C. these

(In the word "these", the underlined "th" is pronounced as /ð/, while the other words have the "th" pronounced as /θ/.)

B. hotel

(In the word "hotel", the underlined "o" is pronounced /əʊ/ while the other words have the "o" pronounced /ʌ/.)

D. stadium

(In the word "stadium", the underlined "a" is pronounced /æ/, while the other words have "a" pronounced /eɪ/.)

D. picture

(In the word "picture", the underlined "t" is pronounced /tʃ/, whereas the other words have the "t" pronounced /t/.)

C. city

(In the word "city", the underlined "c" is pronounced /s/, while the other words have "c" pronounced /k/.)

C. hit

(In the word "hit", the underlined "i" is pronounced /ɪ/, whereas the other words have the "i" pronounced /aɪ/.)