Answer:
a. et al.
Explanation:
In any text citations, specially the name of the authors is a must. Though the citations may differ in their styles for different ways of including the names of the authors, the most common form of citation is to include the last name of the author, followed by the first and middle names, if any.
In cases of numerous authors, in-text citations becomes a bit more complicated. The accepted way of putting an in-text citation for a text with numerous writers is to put the name of the first author followed by the term "<em>et al</em>', which, in Latin, means "<em>and others</em>". This way, it makes it more simpler and easier to cite the referenced text without missing the important details.
Answer:
Se necesita una imagen para ayudarte no puedo hacer nada con tu pregunta
D would be the answer because an imperative sentence is more of a request
