The correct answer is (d) The number of plants and birds increases and the number of snail decreases.
Green plants are eaten by snails, snails by birds, and birds by household cat. If cat is removed from the cycle then the number of birds will increase which will decrease the number of snail in the environment. As there are large number of birds there will be a great demand of snails as a food for birds. Then there will be a decrease in the number of snails because of over eating of snails. There will be an increase in the number of garden plants because very less number of snails are left that will eat garden plants.
Complementary nature of structure and function.
If, and only if, makes it bi conditional.<span />
