It is a hot day at the beach. Ice water costs $2 per bottle and this is your only option. Your marginal benefit for water follows the equation MB = $10 - $x. x is represents the number of bottles of ice water you have had. So, for example, the marginal benefit of the first bottle is $10 - $1 = $9. The MB of the 2nd bottle is $8 .. and so on. Assuming you are an economically rational consumer how many bottles of water will you buy? A. 2 definitely B. 3 definitely C. Either 2 or 3 (you are indifferent on the 3rd bottle) D. 8