Was your average experimental mass percent of oxygen in potassium chlorate higher or lower than the theoretical value (circle one)? Higher/Lower

Which of the following sources of error could be used to explain this discrepancy (circle one)?
a. The potassium chlorate sample was not heated strongly or long enough.
b. Some of the potassium chloride product splattered out of the crucible during the heating process.
Explain your choice. Your response should include an analysis of the calculations you performed with your raw data to obtain your experimental % of oxygen.

Average experimental mass percent of oxygen in potassium chlorate = 44%
The theoretical value = 39%​