What prevents acetylcholine from accumulating in the neuromuscular junction and causing a sustained contraction in a normal individual

Botulinum toxin

Explanation:

Botulinum toxin is known to hinder the release of acetylcholine into the synaptic cleft at the neuromuscular junction.

This leads to acetylcholine not attaching to its receptors and eventually leading to the inability to have muscle contractions.

Hence, in this case, the correct answer is Botulinum toxin prevents acetylcholine from accumulating in the neuromuscular junction in individuals.

not too sure but maybe in the hot springs.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.