For a final product the time$-$phased net requirements for four weeks are given in the table below. The setup costs are K $=120$ and the holding cost per unit and week are h $=2.$ The orders are released on a Silver$-$Meal basis. Which of the following statements are correct?

Week

$1$

$2$

$3$

$4$

Time$-$phased net requirements

$20$

$30$

$50$

$25$

Question $2$ Select one or more:

a$.$

The planned order release in week $2$ is $105.$

b$.$

The planned order released in week $3$ is $75.$

c$.$

The planned order release in week $2$ is $0.$

d$.$

None of these.

e$.$

The planned order release in week $3$ is $50.$

f$.$

The planned order release in week $2$ is $30.$