A market is oligopolistic when: there are spillover effects. there are only a few sellers. income effects outweigh substitution effects. production functions have constant returns. Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key. Here is Jim's willingness to pay for shirts: Number of Shirts Willingness to Pay 1 $10.01 2 $8.00 3 $3.00 4 $1.00 If a seller makes an all-or-nothing offer of take three shirts or nothing, what is the highest price it can charge Jim and still make the sale? $21.00 $10.00 $9.00 $3.00 Choose the most correct answer by clicking a button, or by typing a letter from the keyboard and pressing the tab key.