Answer: A. Están durmiendo
The present progressive is formed by first conjugating the verb estar or seguir depending on context to the subject and then attaching a gerund of the verb that follows. The past (imperfect) progressive simply requires the estar or seguir to be conjugated …
Present tense – Wikipedia
Preterite – Wikipedia
Present tense – Wikipedia
Present tense – Wikipedia
The continuous and progressive aspects (abbreviated CONT and PROG) are grammatical aspects that express incomplete action (“to do”) or state (“to be”) in progress at a specific time: they are non-habitual imperfective aspects.. In the grammars of many languages the two terms are used interchangeably. This is also the case with English: a construction such as “He is washing” may be described …
The conditional mood (abbreviated cond) is a grammatical mood used in conditional sentences to express a proposition whose validity is depende…