The answer is (d), sample randomly in all the habitats potentially impacted by the new marina.
Random sampling minimizes bias. Sampling in all the habitats potentially impacted by the placement of the new marina fulfills the information requirements of the client. Answer e, however, may be more cost-effective in the long run, since having information on the ecological resource values of all the habitats puts the mayor and the resource manager in a better position to address a broader range of resource management questions. You might want to tell the mayor that it would be best to randomly sample all the habitats!