Choose the word that has the underlined part pronounced differently for the rest

I.         Choose the word that has the underlined part pronounced differently for the rest.

1.      a. this                           b. think                        c. thank                       d.thieves

2.      a. gather                      b. bathe                       c. birthday                   d. weather

3.      a. tooth                        b. breathe                    c. through                    d. earth

4.      a. thirty                        b. than                         c. therefore                  d. those

5.      a. mouth                      b. Thursday                 c. nothing                    d. worthy