3A $\to$ C + D, For this reaction it is observed that when initial concentration of A is 10 mole/lit then t1/2 value of this reaction is 40 min and when initial concentration of A is 20 mole / lit, t1/2 value has been changed into 20 min. Which of the following is true?

(1) The reaction is bimolecular reaction

(2) This reaction is an example of radioactive disintegration

(3) The reaction is of 1st order

(4) The order of the reaction is two