Consider the following reaction,

$A+2B\to P$

Rate equation is given as $\frac{-d\left[B\right]}{dt}=K\left[A\right]$ is valid for all concentrations of A & B. Equal volumes of 0.4 M A and 1.2 M B solutions are mixed. If $K=6.93\times {10}^{-4} {\sec }^{-1},$ correct statement(s) is/are 

Time taken for B to become its concentration half is 1000 sec

Rate of reaction at 2000 sec is $6.93\times {10}^{-5}mol{L}^{-1}{\sec }^{-1}$

Time taken for concentration of P to become 0.4 M is $6\times {10}^3$ seconds

Rate of product formation exponentially increases with time