In a gusseted base, when the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate A. Fully by direct bearing B. Fully through fastenings C. 50% by direct bearing and 50% through fastenings D. 75% by direct bearing and 25% through fastenings

The correct answer is A. Fully by direct bearing.

When the end of the column is machined for complete bearing on the base plate, then the axial load is assumed to be transferred to base plate fully by direct bearing. This is because the machined surface provides a smooth and even surface for the column to bear on, which results in a more efficient transfer of load.

Option B is incorrect because the axial load is not transferred fully through fastenings. The fastenings are only used to hold the column in place and to prevent it from rotating. The actual transfer of load is through direct bearing.

Option C is incorrect because the axial load is not transferred 50% by direct bearing and 50% through fastenings. The axial load is transferred fully by direct bearing.

Option D is incorrect because the axial load is not transferred 75% by direct bearing and 25% through fastenings. The axial load is transferred fully by direct bearing.