The correct answer is A. 0.028.
The compression index is a soil property that describes how much a soil will compress when it is loaded. It is calculated by dividing the difference between the void ratio at the liquid limit and the void ratio at the plastic limit by the difference between the liquid limit and the plastic limit.
The liquid limit is the water content at which a soil will flow like a liquid. The plastic limit is the water content at which a soil will just begin to crumble when rolled into a thread 1/8 inch in diameter.
A remoulded sample is a soil sample that has been disturbed by remolding, such as by mixing or kneading.
The value of compression index for a remoulded sample whose liquid limit is 50% is 0.028. This means that when the soil is loaded, it will compress by 2.8% for every 1% increase in water content.
The other options are incorrect because they do not represent the correct value of compression index for a remoulded sample whose liquid limit is 50%.