For a positively charged particle moving in X-Y plane initially along the X-axis, there is a sudden change in its path due to the presence of electric and/or magnetic fields beyond P as shown in fig. The curved path is

shown in X-Y plane and is found to be non-circular. Which one of the following combinations is possible ?

• A

  $\mathrm{E}=0;\mathrm{B}=b\mathrm{j}+c\mathrm{k}$

• B

  $\mathrm{E}=a\mathrm{i};\mathrm{B}=c\mathrm{k}+b\mathrm{j}$

• C

  $\mathrm{E}=0;\mathrm{B}=\mathrm{cj}+\mathrm{bk}$

• D

  $\mathrm{E}=a\mathrm{i};\mathrm{B}=c\mathrm{k}-b\mathrm{j}$