To make it parallel I would say to put it in this format: We can’t go back; to go forward is our only option. This makes the verbs the same.
How many light bulbs we talking about here?
<span>it is 20254 because you times both together<span><span><span><span><span>
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Rule 1. A subject will come before a phrase beginning with of. This is a key rule for understanding subjects. The word of is the culprit in many, perhaps most, subject-verb mistakes.
A bouquet of yellow roses lends color and fragrance to the room.
Rule 2. Two singular subjects connected by or, either/or, or neither/nor require a singular verb.
My aunt or my uncle is arriving by train today.
