[单选题]
A 2.0-kg mass is attached to the end of a horizontal spring of nhy7z59 aw8q:mbtoj 8:rsq1 ssp0hvbiibw/9ooyj 4 4 g7ring constant 50 N/m and set into simple harmonic motion with an a9 0bjy 4hvogow/ib4i7mplitude 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. $1.0 \; J$