Word Formation Reasoning Quest...

The below series uses a sequence of alphabets and numbers. Identify the incorrect combination: 

(i) FT85DF77ER

(ii) FT85DF77ER

(iii) FT85DE77ER

(iv) FT85DF77ER

From the following alternatives, select the word which cannot be formed using the letters of the given word -

  TOKENISM

From the following, select the word which cannot be formed using the given word -

TEACHER

In the following question, select the word which can be formed using the letters of the word STICKLEBACK? 

From the given alternatives, select the word which can be formed using the letters of the given word.
RHINOCEROS