The word "judicious" means having or showing good judgment, discretion, or wisdom in making decisions. In the given sentence, the phrase "choosing one's career" implies the act of making a significant life decision. When selecting a career, it is important to use good judgment and wisdom, as this decision can have a profound impact on one's life and future.

"Judicial" (option 1) pertains to the legal system and judges, so it is not the appropriate word in this context.

"Notable" (option 3) means remarkable or deserving attention but does not convey the idea of making wise decisions.

"Observance" (option 4) means the action or practice of following a custom, rule, or law. It does not fit the context of choosing a career.

The word "judicious" perfectly fits the sentence because it emphasizes the importance of making wise and thoughtful decisions when selecting a career, which is the intended meaning of the sentence.