ANS:D - 1.625 D.

The overall depth of a new egg-shaped sewer section can be expressed in terms of the diameter of the upper circular portion (D). The egg-shaped sewer section typically consists of a circular upper portion and a lower elliptical or egg-shaped portion. The relationship between the diameter of the upper circular portion (D) and the overall depth of the sewer section can be expressed as follows: Overall Depth=k×D where k is a constant factor that depends on the specific design of the egg-shaped sewer section. The value of k can vary depending on the specific design standards or specifications used. However, commonly used values for k range between approximately 1.25 to 1.75. Given the options provided, let's try each one using the diameter of the upper circular portion (D):

1. Overall Depth=1.250×D
2. Overall Depth=1.350×D
3. Overall Depth=1.425×D
4. Overall Depth=1.625×D

By comparing these options, we can determine which one is correct based on common values of k used in engineering standards. Typically, a value around 1.25 to 1.35 is commonly used for k in egg-shaped sewer designs. Therefore, the correct option would likely be either 1.250 D or 1.350 D. However, without specific information regarding the design standards or specifications being used, it's challenging to determine the exact value of k and thus the correct option.