Goods or services that are similar to one another from the
consumer's perspective are known as Equal goods.
Because equal goods are those goods which can be same in quantity,
size or value. Hence, option(c) is correct.
Example of substitute goods is Coke and pepsi.
Because substitute goods are those which can be replace or
substitute by each other. These are the goods which gives benefits
or same satisfaction. As coke and pepsi both are drinks and black
in colour , therefore substuting coke with pepsi or pepsi with coke
doesn't reduce the consumer benefits. If price of one good
increases , then demand for other good (i.e substitute) increases.
Hence, option(e) is correct.
Complements are goods or services that consumers use
together in some way . Because complements are goods which
are consume together . For example: Car and petrol. Without petrol
, there is no use of car. Therefore, they both are consume
together. As price of petrol rises, demand for cars decreases.
Hence, option(a) is correct.