Final Answer:
To complete the equation h(x)=g(x)+c, a possible form for c is a quadratic function (Option C).
Step-by-step explanation:
Given g(x) = -x^2−2x+5, the sum of g(x) and a quadratic function c would yield h(x)= −x^2 −2x+5+c. A quadratic function involves terms up to x^2, making it compatible with this expression. On the contrary, linear and exponential functions would introduce terms beyond quadratic, altering the form of the equation. Therefore, c being a quadratic function ensures compatibility with the given expression, making Option C the correct answer.