[求助]JJ一題!拜託牛牛幫忙澄清思路

If k = -1, which of the following is (are) true?

I. k^k = k

II. |k| = -k

III. k⁰ = -k

A. I only

B. I and II only

C. I and III only

D. II and III only

E. I, II, and III

ANS:c

MINE  :e 

想請教牛牛們 2問題

(1)why II   IS WRONG

(2)有關絶對值的定義

if   k<0,   |k|=-k

if   k>0    |k|=k

但本題k=-1<0    |k|=1  就不符合絶對值的公式

if   k<0,   |k|=-k

我都暈了請牛牛們指正我到底哪裏有問題

我也选E

我也觉得是E

E too,but why wrong??