A project manager is developing a website to sell 3D printing services. Choose the following items below that would fall into the category of a critical success measure. There are more than 4 answers for this questions; also, consider what is a measure vs. a factor (remember critical success factors).
a. Number of purchases through the website
b. Ease of navigation
c. Length of time that a unique visitor stays on the website
d. Positive feedback about the website
e. Length of time from opening the website to time of purchase
f. Ranking on searches within the market area