Part (a) Which option represents a correctly formed Biot-Savart expression, without simplifications or rearrangements, for the contribution of the current element in the center to the magnetic field at point P=(0,a,0)P=(0,a,0)? (In particular, the original choices for Ids⃗ Ids→ and r^r^ must be clear.) dB⃗ =μ0I4πdxi^×(−j^)a2dB→=μ0I4πdxi^×(−j^)a2 dB⃗ =μ0I4πdxi^×j^a2dB→=μ0I4πdxi^×j^a2 dB⃗ =μ0I4πdxi^×(−k^)a2dB→=μ0I4πdxi^×(−k^)a2 dB⃗ =μ0I4πdxi^×j^d2dB→=μ0I4πdxi^×j^d2 dB⃗ =μ0I4πdxi^×k^a2dB→=μ0I4πdxi^×k^a2 dB⃗ =μ0I4πdxi^×j^adB→=μ0I4πdxi^×j^a