The correct answer is...
I am.
BTW, are you really sure that you are an English teacher? I don �t mean to be rude at all, however, your knowledge of the English language seems to be quite limited... 
Just to let you know: I have just reported your worksheet on telephone phrases since the text was taken from the Internet completely. :o((( Delete it, PLEASE! Thanks.??????????
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Sorry , but you are rude
I am an ENGLISH TEACHER
WE ARE A PERSON SO WE CAN MAKE MISTAKES IT IS NOT A BIG DEAL
AND THE QUESTION
WHO WRITES THIS LESSON ?? We can use the present tense
IT IS not WRONG
But I forget only forget
WHERE IS THE WRONG ?
We are here all to learn not to be rude
I DON �t WANT you to REPLY LADY BIRD
SORRY
DON"T REPLY
Let �s other members reply all my questions
But you never reply
And I never reply to anything from you
For my work sheet, there is no problem with it. O�k I prepare it by using from this site
Where is the problem ?????
I arranged in my way
Don´t download it !!!
Bye