Smoothing a Graph of Observations Made Over a Time Series

Smoothing a graph of observations made over a time series

A) is best done visually by passing a smooth line through the data points.
B) is essentially dishonest and unethical since means or medians are substituted for the real data.
C) can be done by substituting the median of 3 adjacent data points for the original points.
D) can make any pattern of data look like an effect of a program.