Os verbos da frase: “In the first task, the children sorted th...

Os verbos da frase: “In the first task, the children sorted the shapes by color.”, “…since studies have shown that bilinguals…” and “Why does the tussle between two simultaneously active language systems improve these aspects of cognition?” estão respectivamente no.a. simple past, present perfect, simple present.
b. present perfect, simple past, simple present.
c. simple present, present perfect, present perfect.
d. simple past, simple past, present perfect.