a) Sell Jan-2019 Puts at 22.5 strike for $2.50.
If TEVA stock price stays below $22.50 then you'll get the stock for $22.50 minus the $2.50 you'll earn from sold put, so your cost/share will be $20.
If TEVA stock price does go above $22.50 then you'll make $2.50 profit from the sold put.
You may also sell your calls, otherwise if you keep the calls and sell puts then you'll end up with synthetic long, which is same as if you sold the calls you already own and bought the stock instead.
b) If you simply sell your calls for $2.90 and buy the shares for $21.50 right now then your current cost will be $18.60 (though you'll still lose the value of the calls you've already lost).
