Option 1 indicates that both the assertion and the reason are true and that the reason correctly explains the assertion. It`s not correct because while Bangalore does receive rainfall from both the southwest and northeast monsoons, Mangalore actually has a higher average annual rainfall.

Option 2 signifies that the assertion and the reason are true, but the reason does not explain the assertion correctly. It`s not correct because although Bangalore does get rainfall from both monsoons, this doesn`t result in it having a higher annual rainfall than Mangalore.

Option 3 suggests that the assertion is true and the reason is false. It`s incorrect because the assertion is false; Mangalore gets more annual rainfall than Bangalore.

Option 4 suggests that the assertion is false but the reason is true, which fits the situation. Bangalore doesn`t get more rainfall than Mangalore (false assertion), but it does receive rainfall from both the southwest and northeast monsoons (true reason). Hence, the correct answer is 4.