The caterpillar of the geometrid moth strikes when special hairs

Answer must be E.

Meaning :
Here caterpillar does 2 things :

1) it strikes the victim on certain condition(disturbance of the hair)
and
2)it holds the victim (once it is captured on striking)

(A) strikes when special tactile hairs on its body are disturbed,

2 actions must be separated/connected by some connector so we need "and " after disturbed.

Also if i take it as list of actions of moth
so strikes and holds are 2 verbs w/o any connector between them which is wrong.
Also the sentence may mean hair are disturbed after catching the prey

So cause is : catching prey
effect:hair get disturbed
which is meaningless.

Original cause and effect is:
Cause:hair get disturbed
Effect:Moth strikes


(B) striking when special tactile hairs on its body are disturbed, but

here striking is not verb.it is modifier for moth.
So means
there is some particular type of moth which strikes only on its hair getting disturbed ,not the intended meaning.
Also if i take striking as verb
striking and holds are not parallel.
Also holds is verb and as said earlier,striking is not.So no verb in parallel to holds.

(C) which strikes when special tactile hairs on its body are disturbed,

This choice clubs errors of A and B.
Here which refers to moth so
giving meaning of B.

So means
there is some particular type of moth which strikes only on its hair getting disturbed ,not the intended meaning.

Also if i take it as list of actions of moth
so strikes and holds are 2 verbs w/o any connector between them which is wrong.
Also the sentence may mean hair are disturbed after catching the prey

So cause is : catching prey
effect:hair get disturbed
which is meaningless.

Original cause and effect is:
Cause:hair get disturbed
Effect:Moth strikes


(D) which, striking when special tactile hairs on its body are disturbed,

Same error as C for which
Same meaning error as A.

One main issue here is in this option we do not have verb.

The caterpillar of the geometrid moth which, striking when special tactile hairs on its body are disturbed,after capturing its prey, holds the victim so that it cannot escape.

Read it without modifiers(struck out part)
The caterpillar of the geometrid moth which holds the victim so that it cannot escape.

here holds is not verb of main sentence.

here we have subject:

The caterpillar of the geometrid moth

then sub clause:

which :subject of sub clause
holds: verb of sub clause
the victim so that it cannot escape.: object of subclause

so main clause has no verb.

It is like saying

My brother Ram who studies in USA


Then what ?
where is main verb?
if i say:

My brother Ram who studies in USA is the smartest in our family.

here "is" is the main verb.


(E) strikes when special tactile hairs on its body are disturbed and,
So all issues solved here.

Strikes and holds are parallel.
2 actions connected via and so no issues .
E is answer