Consider the following statements about the formation of delta and select the correct answer using the code given below: 1. Heavy erosion in the upper reaches of a river. 2. Absence of tidal waves in front of the mouth of a river. 3. Steeper slope along the coastal area 4. Strong ocean currents along the mouth of a river.

• A. 1, 2 and 3 are correct   
• B.        1, 3 and 4 are correct
• C.        1, 2 and 4 are correct 
• D.        1, 2, 3 and 4 are correct