Which of the following has only `1^(@)` and `2^(@)C` atoms?

Which of the following have only 2^(@) H-atom

Which of the following have only 2^(@) H-atom

Which of the following has only one zero?

Which of the following has only sigma bonds?

Which of the following has only one host ?

Which of the following has only one host ?

Which of the following has only one host ?

Which of the following has only one host ?

Which of the following gate has only one input

Which of the following has no existence? (1) 1^(@)"H-atom" , (2) 3^(@)"C - atom" , (3) 2^(@)"H - atom" , (4) 4^(@)"H-atom"