In the stage of the project life cycle, a major portion of the physical project work performed.

a. identifying
b. defining
c. planning
d. executing
e. closing

executing stage                            

Explanation:

The implementation process refers to the third phase of a lifecycle of project planning, and it is typically the project's lengthiest period. The management team grows the product or service during the execution phase, and provides the finished product to the consumer.

The execution process is the maximum in period since with eight post-phases. The three main phases involve constructing the deliverable, monitoring and control, and reviewing. Thus, from the above we can conclude that the correct option is D.

a) both were commissioned explorers