Does 'stir' have to be in the Present form? Shouldn't it be "stirred"?

[Sabir]

English Language Tests, Intermediate level

ESL/EFL Test #86 "Simple Present (3)", question 10

But Sally changed the subject. "This drink tastes delicious. How did you make it?" -- "I put a drop of ginger ale and a piece of lemon in the alcohol and then ......... thoroughly."

(a) stir
(b) beat
(c) mash
(d) fork

English Language Tests, Intermediate level

ESL/EFL Test #86 "Simple Present (3)", answer 10

But Sally changed the subject. "This drink tastes delicious. How did you make it?" -- "I put a drop of ginger ale and a piece of lemon in the alcohol and then stir thoroughly."

Correct answer: (a) stir

Your answer was: correct
_________________________

Dear sirs,

I made a distinction between Am & Br. English(spelling , pronunciation, or different word or phrases)
but no body cares here because i live in Iraq and i would like to discuss that with university professors so, what is your advise to do?
Sabir

[Lost_Soul]

Hi, Alan

I have a question too. Does "stir" have to be in the Present form? Shouldn't it be "stirred"?
I mean, the question was "how did you make it", and not "how do you make it"

Thanks !