Answer :
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
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