**Core Concept**
When fabricating complete dentures, equilibration is a critical step to ensure even distribution of forces and optimal occlusal function. Selective grinding is a technique used to achieve equilibration, and it should be performed at a specific stage of denture fabrication to maximize its effectiveness.

**Why the Correct Answer is Right**
Rearticulating the dentures with a new series of jaw relation records after processing allows for precise adjustment of the occlusal scheme. This step enables the dentist to redistribute the forces evenly across the denture-bearing areas, ensuring optimal distribution of pressure and preventing uneven wear. The use of a new jaw relation record ensures that the denture is adjusted to the patient's current occlusal scheme, accounting for any changes that may have occurred since the original jaw relation record was obtained. The rearticulation process allows for the selective grinding of specific areas, enabling the dentist to make precise adjustments to the occlusal scheme.

**Why Each Wrong Option is Incorrect**
**Option A:** Rearticulating using the original jaw relation record may not accurately reflect the patient's current occlusal scheme, leading to inadequate equilibration and potential occlusal disharmony.

**Option C:** Equilibrating the dentures in the patient's mouth can be challenging and may lead to over-grinding or under-grinding of specific areas, compromising the occlusal scheme.

**Option D:** Spot grinding in the patient's mouth is a temporary solution and may not address the underlying occlusal issues, leading to ongoing problems with denture function and stability.

**Clinical Pearl / High-Yield Fact**
When equilibrating complete dentures, it's essential to remember the "three-point rule": the occlusal scheme should be designed to distribute forces evenly across three points of contact in the posterior (molars), anterior (anterior teeth), and superior (palatal) regions of the denture-bearing area.

**✓ Correct Answer: B. Rearticulated with a new series of jaw relation**