[单选题]
A 2.0-kg mass is attached to the end of a horizontaljd+b15kbb2 nw:y*id x h.o-q j spir1r f ax7vr/;ring of spring constant 50 N/m and set into simple harmova; xr7/i1 frrnic motion with an amplitude of 0.10 m. What is the total mechanical energy of this system?
A. $0.020 \; J$
B. $25 \; J$
C. $0.25 \; J$
D. $1.0 \; J$
