amqata

nevCFA's logic is the right one but I think that he/she's missed that it's a short position, not a long position.

The investor is short - he's a seller - so he loses out if the price of the future RISES. He's locked in at $8/ounce whereas new sellers are getting more than that.

So, you can rule out A and B straightaway.

If the price rises by more than the initial margin less the maintenance margin, then he will have to put up more $$$. The amount that each future has to rise by is ($2,025 - $1,500) / 5000 = 10.5c. So, if the price rises above $8.105/ounce ($8.11 - answer C) then he's up for a margin call.

Try not to use the total value as the denominator, always work back to a per-future value for these sorts of questions.

HTH