Select the most appropriate and grammatically correct adjective to fill in the…

Concept

In an adjective-based fill-in-the-blank question, the correct choice must both grammatically and semantically collocate with the noun it modifies, and it must match the tone or consequence stated elsewhere in the sentence. An adjective that is valid English but describes the wrong kind of subject, or contradicts the sentence's implied outcome, is not the intended answer.

Application

Here the blank modifies "rise in the temperatures", and the sentence states the consequence as "sends jitters around the world" -- a strong, alarmed, worldwide reaction. This means the rise must be sudden and striking enough to cause alarm. "Dramatic" precisely conveys a change that is sudden, striking, and attention-grabbing, matching "sends jitters around the world". Hence "dramatic" is the correct adjective.

Contrast

• "Hesitant" describes a person's uncertain or reluctant manner (for example, a hesitant reply); it does not naturally describe a change in a physical quantity like temperature.

• "Faint" describes something slight or barely perceptible; such a minor change would not "send jitters around the world".

• "Welcoming" describes something friendly or pleasant; a change with that connotation would not provoke alarm ("jitters").

Since "dramatic" alone conveys a sudden, striking change that fits the alarmed, worldwide reaction described, it is the correct adjective: "A dramatic rise in the temperatures sends jitters around the world."