Which of these sentences uses the infinitive as a subject?
a. "to err is human; to forgive is divine."
b. when i wrecked the car, it took a long time for dad to forgive me.
c. have you ever heard the saying "sometimes it is easier to forgive than to forget"?
d. still, he passed up many opportunities to forgive me.

The correct answer is A. "To err is human; to forgive is divine."

Explanation:

In grammar, an infinitive includes the preposition "to" and a verb in its bare form, for example, "to cook", "to live", etc. Additionally, infinitives can be used as subjects if these are the entities that perform the action or the entities described using a linking verb, for example, "To cry is useless".

According to this, the sentence that includes an infinitive as a subject is A. "To err is human; to forgive is divine" because in this the infinitives "to err" and "to forgive" are the entities described by the linking verb "to be" and therefore the subject in two different sentences.

is that the whole question?

the author develops a cold, and scared tone. making the reader shudder with fear, and suddenly become cold. i'm guessing that he's writing a scary novel, or maybe about a chilly december night.