I'm not sure, but my best answer would be "C". Hope this helps, sorry if it doesn't.
Answer:
Transport proteins play a role in both active and passive transport to move molecules across the plasma membrane
In general, stem cells have 3 main properties:
1) They are capable of dividing and renewing for long periods of time.
2) They are unspecialized cells.
3) They can give rise to specialized cells.
