The letter C because Parallel structure is basically something that is written short but says everything that its suppose to mean.
I think it’s “a” will decay when discarded as trash .. but im not sure srry if im wrong
Her average speed is 6 km per hour.
1a) Due to poor weather
1b) Because of safety concerns
1c) As a result of the last incident.
2a) Due to his bad grades.
2b) Because of his lack of study
2c) As a result of his mother's critical illness.
3a) Due to complications
3b) Because of improper supervision
3c) As a result of lack of fuel.
{this is what I could come up with }
Hope this helps.
Good luck.
