(1) one final effect of radio and television on the english language should be noted. (2) there is no doubt that these great media of information have considerably reduced the time that used to be devoted to reading. (3) radio and television may enhance the spoken word. (4) however, they may develop audiences who do not know how to think independently.

select the correct answer.

which numbered sentence is the topic sentence?
a. 1
b. 2
c. 3
d. 4