Abiotic factors are are not living, while biotic factors are. Grass is living, so it would be a biotic factor.
Answer:
Sickle cell anaemia is what I think is the answer
An insulating plate, such as plastic, tends to be positively charged when rubbed with cloth due to the piezoelectric effect. This phenomenon involves certain materials to generate charged particles as a response to mechanical stress applied to it. In this case, the mechanical stress was due to the rubbing motion.