[单选题]
A 2.0-kg mass is attached to the end of a horizontal spring oftlc4k1zh.* ek spring co h v5cpp777q,syvqn -rnstant 50 N/m and set into simple harmoq 77r7- p5hcpvyvqsn,nic 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. $1.0 \; J$
