Answer:
The correct possessive form of the singular noun needed to complete the sentence is dragonfly’s.
A dragonfly’s speed can reach up to 30 miles per hour.
Step-by-step explanation:
To form the possessive form, an apostrophe and an 's' is added to the noun. This happens when the noun is singular in number. When the noun is plural an apostrophe is added after the 's' in the noun.