Choose the One Alternative That Best Completes the Statement or Answers

Multiple Choice

Choose the one alternative that best completes the statement or answers the question.
-A particular substance decays in such a way that it loses half its weight each day. How much of the substance is left after 7 days if it starts out at 16 grams?

A) 4 grams
B) $\frac { 1 } { 8 }$ gram
C) $\frac { 1 } { 4 }$ gram
D) 8 grams