Answer:
Entienda is the correct answer leaving the phrase as it follows: Es posible que el estudiante no ENTIENDA la lección.
Explanation:
Entienda is conjugated in the subjunctive form (modo subjuntivo), which is used to express wishes, petitions or possibilities.
The words entenda and entende are misspelled, as mentions the first two options. Whilst the word entiende, as mentions the third option, is written in the indicative form (modo indicativo) which doesn’t express a possibility, but the way how things actually are.
