Given the graph of [math] below, at which of the marked [math]-values can the following statements be true?

(For each question, enter your answer as a comma-separated list, e.g., x1,x3,x5. Enter none if no points satisfy the given condition)
A. [math] at [math]
B. [math] at [math]
C. [math] is decreasing at [math]
D. [math] is decreasing at [math]
E. The slope of [math] is positive at [math]
F. The slope of [math] is positive at [math]