if the conversion cost per equivalent unit was $$0\mathrm{.}25$ per gallon in June, what is the difference in the conversion cost per equivalent unit between the two months?

a$.$ $$1\mathrm{.}00$

b$.$ $$0\mathrm{.}10$

c$.$ $$0\mathrm{.}75$

d$.$ $$0\mathrm{.}35$