Concept:
- Letters from one font repeat the same design rules for stroke thickness, serif shape, curves, and proportions.
- A word is valid only if every required letter follows one consistent set of these features.
Step 1: Choose features that can be compared.
Trace each option in the letter field and compare the ends of strokes, the thickness of vertical lines, the shapes of bowls, and the overall height-to-width proportions.
Step 2: Eliminate the mixed-font words.
The letters needed for knowing, pester, and navel include visible changes in weight, serif treatment, or proportion. Each of these words therefore mixes font designs.
Step 3: Check the remaining sequence letter by letter.
The letters $d,e,l,i,g,h,t$ share the same light stroke treatment, serif details, and balanced proportions in the image. They form one consistent typeface.
Final Answer: delight, option C.