Which of the below is a project? $[4$ marks$]$

$($More than one answer applied.$)$

Question $1$Answer

a$.$

Develop new features and make major changes to enhance the current software application.

b$.$

Adding features to an on$-$going software development.

c$.$

Monthly update for software applications.

d$.$

Develop a software application based on customer's order.

e$.$

Maintenance for software application after development completion.