The observed staff reading is 2.5 m, on a staff which was improperly held at a station such that its slope was 20 : 1. The correct staff reading will be:

The observed staff reading is 2.5 m, on a staff which was improperly h

1.	The observed staff reading is 2.5 m, on a staff which was improperly held at a station such that its slope was 20 : 1. The correct staff reading will be:
A.	\(\frac {51}{\sqrt {399}}m\)
B.	2.8 m
C.	\(\frac {20}{7}m\)
D.	\(\frac {50}{\sqrt {401}}m\)
Answer» E.