9. choose between the following verbs those that change from o to u. almorzar costar comprar comer recordar

Brief Explanations:

To determine which verb changes from "o" to "u", we analyze the conjugation of each verb (in the present subjunctive or other relevant tenses for stem - changing verbs).

• "almorzar" has a stem - change of "o" to "ue" (e.g., "almuerzo" in the present tense, but the stem - change here is not "o" to "u").
• "costar": In its conjugation (e.g., in the present subjunctive "cueste", the stem - change is from "o" to "u").
• "comprar" is a regular verb with no stem - change involving "o" to "u".
• "comer" has a stem - change of "e" to "ie" (e.g., "coma" in subjunctive, not related to "o" to "u").
• "recordar" is a regular verb (or has a stem - change of "o" to "ue" in some tenses, not "o" to "u").

So the verb that changes from "o" to "u" is "costar".

Answer:

The checkbox next to "costar" should be selected.