Despite Ruel's aptitude, experience, and wide range of skills, the corporation rejected his application for CEO.
The sentence suggests that despite Ruel's qualifications, experience, and skills, the corporation did not accept or approve his application for the position of CEO.
In this context, the most appropriate word to fill in the blank is "rejected" (option B), as it accurately conveys the idea that the corporation did not approve or grant Ruel the position. The other options may not convey the same sense of denial or refusal in the context of a job application.
The correct option is b.