Assume that a client has the following needs and objectives when purchasing a life insurance policy:

Flexible premium payments

$--$ Possibility of increasing death benefit

Investment options

Permanent protection

Choose the type of policy that is most suitable $($there is one answer$)$ for this client and explain why. Also explain why the others are not suitable. Short explanations only.

A$.$ Whole life

B$.$ Universal life

C$.$ Variable life

D$.$ Variable universal life