Intent: CC refused to accept a conventional wisdom, He had to endure a lot for the acceptance of a voyage.

A) Refusing to accept the conventional wisdom that the earth was flat, Christopher Columbus pressed tirelessly for royal support for a westward voyage to Asia, enduring several rejections before securing
Correct Answer as per the intent

B)Christopher Columbus refused to accept the conventional wisdom of the earth being flat; he pressed tirelessly for royal support for a westward voyage to Asia and endured several rejections, finally securing
Being - Earth was not in the process of being flat, it was thought to be flat -> Eliminate

C) Refusing to accept the conventional wisdom of the earth being flat, Christopher Columbus pressed tirelessly for royal support to sail westward to Asia and to endure several rejections; he finally secured
and conjunction is present without parallelism

D) Christopher Columbus not only refused to accept the conventional wisdom that the earth was flat, he pressed tirelessly for royal support for a westward voyage to Asia, endured several rejections, and he finally secured
Not Only X incorrectly used. No contrast is present.

E) Refusing to accept the conventional wisdom that the earth was flat, Christopher Columbus's effort was tireless in pressing for royal support for a westward voyage to Asia; he endured several rejections before the securing of
Effort wont Refuse -> Out
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If you notice any discrepancy in my reasoning, please let me know. Lets improve together.

Quote which i can relate to.
Many of life's failures happen with people who do not realize how close they were to success when they gave up.