Which is a correctly written sentence, not a run-on?

ATomatoes in our garden are ripening; they will be delicious in a salad.
BDog-sitting is fun and challenging it takes patience and organization.
CJacaranda trees have fernlike leaves, they bloom purple flowers in spring.
DA bird laid eggs in a nest on the patio they should be hatching soon.

Verified Answer :

ayah1

All these sentences need a semicolon (;)

a. Tomatoes in our garden are ripening; they will be delicious in a salad.
b. Dog-sitting is fun and challenging; it takes patience and organization.
c. Jacaranda trees have fernlike leaves; they bloom purple flowers in spring.
d. A bird laid eggs in a nest on the patio; they should be hatching soon.

The answer is A. because it already has a semicolon