Final answer:
The correct answer to what 'incompletely' means in the given context is B) partially, indicating that the students should read the directions to some extent but not thoroughly.
Step-by-step explanation:
You asked about the meaning of the word 'incompletely' as used in the sentence: 'The teacher instructed her students to read the directions incompletely prior to beginning their assignment.' In this context, the correct answer is B) partially. This means that the students are being asked to read the directions only to some extent, but not fully or completely.
To explain further, if something is done incompletely, it is not done entirely or to the full extent. Therefore, when someone reads directions partially, they read only a part of them. The word inadequately would imply that the reading was not sufficient in quality, while conscientiously would suggest that the reading is done with great care, which contradicts the sense of doing something incompletely. Deficiently and incompetently would not be appropriate in the given sentence as these words suggest a lack of skill or ability rather than the extent of completeness.