An increasing number of people _______ handheld devices to access the Internet. A. is using B. was using C. are using D. has been usi

The incorrect options A, B, and D do not agree in subject-verb agreement or verb tense with the sentence.

The use of the present continuous tense 'are using' indicates an action that is currently happening.

The verb 'are using' agrees with the subject 'people' which is plural.

The correct answer is C, are using.

An increasing number of people are using handheld devices to access the Internet.