● Maintenance activities include（74）. ①making enhancements to software products ②developin

● Maintenance activities include（74）.

①making enhancements to software products

②developing a new software product

③correcting problems

④adapting products to new environments

（74）

A．①②

B．①③④

C．②③④

D．①②③④

请帮忙给出正确答案和分析，谢谢！