What is the annual equal amount of money you have to set aside to guarantee yourself an annual income to perpetuity of $$15,000$ starting in $41$ years from now? You make the first payment in three years from now and the last payment in $40$ years. Assume an interest rate of $7\%($EAR$).$

Options for answers are:

$1249$

$1242$

$1329$

$1073$

$1235$

$18595$

$1161$

$1000$

I've asked this question before but the expert just seemed to pull numbers out of nowhere when calculating PMT at the end...