Correct option is A
Canal escapes are irrigation structures constructed to discharge excess water from a canal into a natural channel or drain.
(1) Weir-type escape:
The crest of the weir wall is kept at R.L. equal to the canal full supply level (FSL).
When the water level rises above FSL, it gets escaped.
Crest level = FSL of the canal
(2) Regulator/sluice type escape:
This may be constructed for the purpose of scouring off excess bed silt deposited in the head reaches from time to time.
The silt of the escape is kept at canal bed level and the flow can be used for completely emptying the canal.
