This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to get rid of garden slugs
Use beer or milk traps for important plants.
Slugs will only notice these traps from a few feet (about a meter) away, so this is best used for small gardens or important areas. Set these up as follows :
Bury a tall cup with steep sides into the soil.

OPT: (A). Make a shallow ditch for drainage inside the puddle. Leave about 1 meter (45 in) of space between the soil and the rim of the cup. (B). Leave the rim inch (1.25 cm) above the soil, to prevent the trap killing beetles that hunt slugs. Fill the cup halfway with beer or milk. (C). Stick a piece of chicken wire beneath the body of the cup. Hold the cup upright for as long as it takes to insulate the soil. (D). Give it a few inches to cool off. Place your walking stick/stake under the upright base and next to the carrying handle.
The answer is:
(B).