The correct answers are I bought a umbrella, She found an unique gift, and He is a honest salesperson.

"A umbrella" is wrong—"umbrella" starts with a vowel sound /ʌ/, so use an umbrella. "An unique" is wrong—"unique" starts with /juː/ (a consonant sound), so use a unique. "A honest" is wrong—"honest" has a silent h, starting with /ɒ/, so use an honest.