The correct answer is (c) 92%.
22 carat gold is an alloy of gold and other metals, such as silver, copper, and zinc. The purity of gold in 22 carat gold is 92%, meaning that it is 92 parts gold and 8 parts other metals.
The other options are incorrect because they do not represent the actual purity of gold in 22 carat gold. Option (a) is incorrect because it states that the purity of gold in 22 carat gold is 100%. This is not accurate, as 22 carat gold is an alloy and not pure gold. Option (b) is incorrect because it states that the purity of gold in 22 carat gold is 99%. This is also not accurate, as 22 carat gold is an alloy and not pure gold. Option (d) is incorrect because it states that the purity of gold in 22 carat gold is 75%. This is also not accurate, as 22 carat gold is an alloy and not pure gold.