Randy kept digging into the past of Matthew against their will, because 
OPTIONS:
- Randy was trying to hide the truth.
- Matthew was trying to hide the truth.
Matthew was trying to hide the truth.

Tanya got her first period well before Victoria, because 
OPTIONS:
- Tanya started puberty at a later age.
- Victoria started puberty at a later age.
Victoria started puberty at a later age.

Brian wanted to teach Robert how to paint using watercolors because 
OPTIONS:
- Brian was a good teacher.
- Robert was a good teacher.
Brian was a good teacher.