The exhausted firefighters we’re tremendously relieved when the other brigades arrived.
Which of the following corrects an error in the sentence above?

"Replace we’re with were" is the correct answer. This is correct because we’re is a contraction of we and are, while were is a verb.
"Replace relieved with releived." This is incorrect because of the I before E rule.
"Replace exhausted with exausted." This is incorrect because the h in exhausted is silent.
"Replace firefighters with firefighter’s." This is incorrect because firefighters is a plural noun, whereas firefighter’s is a possessive noun.