The correct answer is A. active voice.
When the subject performs a particular action, it means that the sentence is active rather than passive. If the object was the focus of the sentence, then it would be a passive sentence.
For example: I love reading books - active sentence
Books are written by writers - passive sentence
These sentences can be in future, past, or present tense - which means that tense is not important.
Paragraph blocks are especially useful in problem-and-solution essays because they allow a writer to explain a problem at length and identify components to a solution - C
