sc - conditional tenses

[demoskopico]

Affording strategic proximity to the Strait of Gibraltar, Morocco was also of interest to the French throughout the first half of the twentieth century because they assumed that if they did not hold it, their grip on Algeria was always insecure. .

(A) if they did not hold it, their grip on Algeria was always insecure
(B) without it their grip on Algeria would never be secure
(C) their grip on Algeria was not ever secure if they did not hold it
(D) without that, they could never be secure about their grip on Algeria
(E) never would their grip on Algeria be secure if they did not hold it

Please full explanations thanks

[ndhji]

E. Conditional clause "if" has past tense---> main clause should be "would+be". E will become confusing if the use of conversion ("never would" on the begin of the main clause) is neglected.

[kevin]

What does 'it' refer to? Do you think we should use grip and hold in the same sentence?

[ykaiim]

(B) without it their grip on Algeria would never be secure

This is simple and in sync with the PAST tense in the main clause, "Morocco was also of". Also, "it" is used for Morocco while "their" is used as possesive pronoun for the "French" (later in the sentense referred by "they").