Answer:
Una variable de control (o constante científica) en la experimentación científica es un elemento experimental que es constante y sin cambios durante el curso de la investigación. ... Las variables de control en sí mismas no son de interés primario para el experimentador.
Explanation:
I'm sure it's Quarts, the answer would be D
Answer;
Endocytosis process
The vesicular process involved in the toxin entering the neuron is endocytosis process.
Explanation;
Endocytosis is a vesicular process, that involves capturing a particle or a substance from the outside of a cell by engulfing it with the cell membrane, and bringing it into the cell.
Botulinum toxin binds to the neuronal cell membranes at the nerve terminus and enters the neuron by endocytosis.