10 An advertising firm has D dollars to spend on reaching customers in T separate markets. Market t consists of kt people. If x dollars are spent on advertising in market t, the probability that a given person in market t will be reached is pt(x). Each person in market t who is reached will buy ct units of the product. A person who is not reached will not buy any of the product. Formulate a dynamic programming recursion that could be used to maximize the expected number of units sold in T markets.