A company produces two products. Each product can be produced on either one of three machines. The time $($in hours$)$ required to produce each product on each machine is shown below:

Machine $1$

Machine $2$

Machine $3$

Product $1$

$5$

$4$

$6$

Product $2$

$8$

$5$

$5$

Each month, $600$ hours of time are available on each machine, and that customers are willing to buy up to the quantities of each product at the prices that are shown below:

$$

Demands

Prices

Month $1$

Month $2$

Month $1$

Month $2$

Product $1$

$120$

$200$

$$60$

$$15$

Product $2$

$150$

$130$

$$70$

$$35$

$$

The company$$s goal is to maximize the revenue obtained from selling units during the next two months.

How many constraints does this problem have $($not counting non$-$negativity constraints$)?$

a$.$

$10$

b$.$

$5$

c$.$

$12$

d$.$

$8$