• “1. The maximum thrust increases slightly as the pressure altitude increases." INCORRECT.

As altitude increases, the air gets thinner. The increase in altitude causes a decrease in pressure, thus a decrease in density and a corresponding decrease in thrust – since less air is entering the gas turbine engine.

• “2. The specific fuel consumption decreases slightly as the pressure altitude increases at constant TAS.” CORRECT.

Specific fuel consumption reduces proportionally to the temperature => If the temperature is decreasing, specific fuel consumption decreases.

That being said, specific fuel consumption depends on temperature and not on pressure altitude. Thus saying that " The specific fuel consumption decreases slightly as the pressure altitude increases at constant TAS." is vague because, even though normally temperature increases with reducing pressure altitude, there can be inversions.

For the sake of the question, we assume standard conditions => temperature decreasing with increasing pressure altitude => specific fuel consumption, therefore, decreases with increasing pressure altitude (inversely proportional).