The ICC mechanical code requires condensate disposal components to be of approved corrosion-resistant material , and the drain line shall not decrease in size from the drain pan connection to the place of disposal.
The code minimum size is 3/4 inch , so the 1/2-inch statement is incorrect, and the code is not limited to PVC only. Also, the slope requirement for horizontal drain piping is not less than 1/8 inch per foot , not 1/4 inch per foot. That makes Option A the only fully correct statement.