question about stock index futures contracts plz!

An investor sold ten March stock index futures contracts. The multiplier on the contract is 250. At yesterday’s settlement price of 998.40 the margin balance in the account was computed as \$86,450. Today the index future had a settlement price of 1000.20. The new margin amount is:

Is it 81950?

i got 81950 as well

can u guys write out your answers? so we see where you are getting that?

why does the value go down when the investor is long futures? the multiplier is 10 x 250 contracts. therefore \$1 mvmt in price is 2500. price has increased \$1.80, which is a \$4500 price mvmt. shouldnt it be \$90950? a short contract would be 81950 (although per my earlier question im not an expert on this stuff!!)

without any of the answer choices I’d also guess it’s \$90,950 (1002.8-998.4)*250*10 = \$4,500 on top of the current margin balance intuitively, the short’s margin balance should always increase when the stock or index value increases, so you could eliminate any choices less than \$86,450

Hold on a sec, he sold the contract so that would mean he’s short the index. Am I missing something here? What’s the actual answer? And explanation if given?