Detailed Solution:
The correct answer is “1, 2 and 3”.
A Mayor in Uttar Pradesh, like in most Indian cities, is considered the "first citizen" of the city, is an ex-officio member of the Municipal Corporation, and also serves as the ex-officio Chairman of the Executive Committee.
However, it's important to note that while they are the ceremonial head, they typically do not have full control over the executive machinery, which is usually handled by a Municipal Commissioner.