Consider the following statements regarding the name ‘Punjab’:

1. The term ‘Punjab’ is derived from two Sanskrit words meaning "land of rivers."

2. Ibn-Battuta was the first traveler to refer to this region as Punjab in the 14th century.

3. The Greeks referred to Punjab as ‘Pentapotamia,’ meaning "land of five rivers."

4. During the medieval period, it was known as the ‘Province of Lahore’ under the Mughals.

How many of the above statements are correct?