At expiry of a 4% Payer swaption on a 7-year interest rate swap on $100mln, with 6-mo SOFR as the floating rate leg, the actual (prevailing) 7-yr swap rate is 4.60% and the yield curve is flat. The option is cash settled on the basis of that prevailing swap rate of 4.60%.

Payment dates are every 6 months.

Roughly what is the cash settlement amount of the swaption?

$5.02mln

$3.56mln

$3.817mln

$2.51mln

$4.57mln