Topic: Synonyms,

Best Answer Explained in Below-:

The word "colossal" is an adjective that describes something of immense size, magnitude, or degree, often eliciting a sense of awe due to its overwhelming nature. To understand why "gigantic" is the correct answer among the provided options, we must consider the meanings of each choice.

**A) Bias** refers to a tendency to lean in a certain direction, either in favor of or against something, and is unrelated to size or scale.
**B) Colurful** seems to be a misspelling of "colorful," which describes vibrancy or variety in colors but again does not relate to physical size.
**C) Fantastic** typically means extraordinarily good or attractive but does not specifically denote large size; it focuses more on quality or appearance.

**D) Gigantic**, on the other hand, is a synonym for "colossal." It also pertains directly to something that is extremely large or enormous. Both words evoke similar imagery related to impressive size, making "gigantic" the most appropriate choice. Thus, in this context, when looking to find a word that closely aligns with "colossal," "gigantic" stands out as the most fitting synonym.