Lo único que hacía era defender el triciclo<span>.
All he did was defend the tricycle
</span>
The answer would be
Es necesario “estar” cerca de la costa.
With expressions such as 'es raro que' you need to use the subjunctive form of a verb which is slightly different than the present, indicative form. So, the 'normal' form of ir for third person plural would be van. However, we need the subjunctive form here, which is vayan.
This means that the correct answer is A. Vayan a la escuela los sabados.
The form ven doesn't exist.
Ella es baja.
bajo would be for male
and está wouldn’t make sense.