Which of the following was a drawback of the industrial revolution?

a. the birth of the middle class
b. the development of new consumer goods
c. the use of child labor
d. the development of the transcontinental railroad

A drawback is something negative, something that is not wished for and is detrimental.

Let's just see which of the options is negative?

The negative options is: C, use of child labour, as it takes away opportunities from children to develop properly. And in fact, it was a big problem in the Industrial revolution - so it's the correct answer.

The other options are not negative -  new consumer goods in themselves for example are a good thing!