Test Estimation for off-the-shelf enterprise-wide product

Recently I have faced a question while taking ISTQB exam and I am listing here. Please provide some good answers and why?

Q: Your company is installing an off-the-shelf enterprise-wide product and you are assigned to do test effort estimation. This is the first time your company is doing like this. Which of the following is the best approach to do estimation? a. Based on Development effort and lines of code b. Industry averages c. Based on the Installation Guide d. Do detailed work breakdown and do estimation based on previous projects experience

Not sure which one will be more suitable in this scenario. Just throw some light and we can discuss.