Use the following Cost decision tree and the given expected values, what is the best decision strategy?

EV $2=130\mathrm{.}6$ EV $5=132.$ and there is $1\mathrm{.}4$ cost to conduct the market research.

Note that EV $2$ is not the net of the Do branch. It is calculated based on the EV $3$ and EV $4$ and nothing else is considered.

a$.$

We must run the market research as it leads to lower cost

b$.$

We must run the market research as the expected value of sample information is zero which means do the research

c$.$

We do not recommend the market research as the Don't branch has lowed cost

d$.$

We must run the market research to get revised probabilities

e$.$

We do not run the market research as doing or not doing it does not change our expected cost

Use the following Cost decision tree and calculate the EV at node $2$ given the EV at node $3=140,$ EV at node $4=168.$

P$($s$1)=0\mathrm{.}75$ P$($F$)=0\mathrm{.}7$