Question

Choose a logical response: Welcher Tag ist heute?

schreiben

gern

Samstag

laufen

(Dont answer if you aren't sure please)

Answer 1

It would definitely be Samstag. Since it's referring to a day of the week.

Welcher Tag ist heute? Is asking, what day is it today? So Samstag is the most logical answer.

I only answered this because sometimes we need double of proof towards these things to verify.

Answer 2

The question asks: What day is today?

your options are:

schreiben- the verb to write

gern- gladly

samstag- Saturday

laufen- the verb to walk

So, the most logical response would be Samstag.