You are a wheat farmer that has entered into $10$ short futures contracts with a delivery date $3$ months

from today. The futures price is $$3\mathrm{.}50.$ Each contract covers $5,000$ bushels of wheat and has an initial

margin requirement of $10\%.$ If the futures price changes to $$3\mathrm{.}30,$ by what percentage does your margin

account balance change?

a$.+42\mathrm{.}8\%$

b$.-42\mathrm{.}8\%$

c$.-57\mathrm{.}1\%$

d$.+57\mathrm{.}1\%$

e$.+4\mathrm{.}28\%$