Final answer:
The most appropriate noun to fill in the blank is 'un short,' which translates to 'shorts' in English.
Step-by-step explanation:
The most appropriate noun to fill in the blank in the given sentence is un short. 'Short' in French refers to a pair of shorts that are commonly worn in summer. The sentence translates to 'In summer, I wear shorts.' The options 'des gants' (gloves), 'un pull' (sweater), and 'une parka' (parka) are not suitable choices for summer clothing.
Learn more about Using the correct noun in a French sentence