The smaller horizontal angle between the true meridian and a survey line, is known

ANS:C - azimuth

Azimuth is the smaller angle when the bearing is measured wrt true meridian and expressed in WCB i.e. when the true bearing is less than 180 degrees then azimuth = true bearing but when the true bearing is more than 180 degrees then azimuth = 360-true bearing.

We have to take a smaller angle for azimuth it may be either clockwise or anticlockwise.

Here we have to clarify the difference between true meridian & magnetic meridian.

The first true meridian is true magnetic Poles (North & South) when the horizontal angle of any line is measured with respect to the true meridian the angle is called "true bearing or bearing".

Second Magnetic meridian is imaginary line connecting north & south poles, when the horizontal angle of any line is measured with respect to the Magnetic meridian the angle is called "azimuth". The navigator uses the azimuth for there navigation purpose. True meridian is a north-south line and azimuth is angle reference to North-South mean angle made with north it's called the azimuth. The correct one is C. Because the angle measured from true meridian with survey line & that is horizontal. In WCB or Azimuth angles are measured from North. Azimuth or whole circle bearing angles range from 0 to 360 Degree.

Bearing or reduced bearing angle range from 0 to 90 degree.

As you can see in the question Smaller horizontal angle the correct answer is Bearing.