Write the Number from the List of Engineering Branches or Sub-Branches

Write the number from the list of engineering branches or sub-branches for the most appropriate description. Note that all of the choices will not be used.
-Involved in cleaning up toxic wastes, and rehabilitating abandoned gas-station tanks.

A) Aerospace engineering
B) Agricultural engineering
C) Architect
D) Biomedical engineering
E) Ceramic engineering
F) Chemical engineering
G) Civil engineering
H) Computer engineering
I) Computer science
J) Construction engineering
K) Electrical engineering
L) Environmental engineering
M) Geotechnical engineering
N) Industrial engineering
O) Manufacturing engineering
P) Materials engineering
Q) Mechanical engineering
R) Mining engineering
S) Nuclear engineering
T) Petroleum engineering
U) Structural engineering