An approximate of how much protein does an average adult male require each day?

The correct option is 72g.

To understand why this is the correct estimate, we can look at the dietary guidelines for daily protein intake.
The Recommended Dietary Allowance (RDA) for protein is approximately 0.8 grams of protein per kilogram of body weight per day ($0.8 \text{g/kg/day}$) for an average adult.

For an average adult male, a standard reference body weight is often considered to be around 70 to 90 kilograms (approximately 154 to 198 pounds).
If we calculate the daily protein requirement using a reference weight of 90 kg, the calculation is as follows:

$\text{Daily Protein}=90 \text{kg}\times 0.8 \text{g/kg/day}=72 \text{g/day}$

Thus, 72g represents a very accurate estimate of the daily protein requirement for an average adult male.