Question

look at the text below. if there is an error with subject - verb agreement, select the incorrect verb and type it correctly. otherwise, submit the text without making any changes. when conducting research, be careful in choosing your sources; all is subject to the biases and opinions of their authors.

Explanation:

In the sentence, "all" here refers to "sources" (plural), so the verb should agree with a plural subject. The incorrect verb is "is"; it should be "are" to match the plural subject implied by "all" (referring to sources).

Answer:

When conducting research, be careful in choosing your sources; all are subject to the biases and opinions of their authors.