On a steep section of road, two vehicles meet in a narrow area where they cannot pass each other; the vehicle travelling... has right of way.

A)with the greater maximum authorised mass (MAM).
B)downhill.
C)uphill.Correct
On steep sections of road with no priority signs and which are too narrow for two vehicles to pass each other, the right of way belongs to the vehicle travelling uphill, unless it could reach a designated passing place first.
A steep section is understood to be one with a minimum gradient of 7 per cent.