[CO-OM-CCA] In SAP Cost Center Accounting, which type of posting can be selectively blocked on a cost center by setting the appropriate blocking indicator?

Introduction / Context:
SAP Cost Center Accounting allows organizations to control which postings are permitted on specific cost centers. Sometimes you want to temporarily block certain postings while still allowing others, for example during restructuring, closing periods, or testing scenarios. The blocking indicator on the cost center master record provides this control. Understanding which types of postings can be blocked is important for both daily operations and SAP certification exams that test knowledge of CO master data behavior.

Given Data / Assumptions:
- We are working in the CO Cost Center Accounting component. - A cost center master record includes a blocking indicator that can restrict postings. - The question asks which type of posting can be selectively blocked. - We assume a standard SAP configuration without customer specific enhancements.

Concept / Approach:
In Cost Center Accounting, primary cost postings usually originate from external expenses such as vendor invoices, material consumption, and other Financial Accounting postings. Secondary cost postings are internal allocations, such as assessments or activity allocations. SAP allows you to restrict or block primary costs through settings on the cost center master, thereby preventing unwanted postings. Material withdrawals are represented as primary costs on the cost center but are not a separate blocking type. Commitments are planned future costs and are controlled differently. To answer the question correctly, you focus on which posting category the blocking indicator explicitly supports in the standard system.

Step-by-Step Solution:
Step 1: Recall that the cost center master record has control fields which can restrict postings. Step 2: Consider which posting categories are normally differentiated in Cost Center Accounting: primary, secondary, revenue, and sometimes commitments. Step 3: Understand that material withdrawals are a business process resulting in primary costs and are not usually a distinct blocking category. Step 4: Recognize that commitments are planned obligations, controlled mainly by budgeting and not typically by a cost center blocking indicator. Step 5: Conclude that the standard blocking category that can be selected on a cost center is for primary costs in actual and plan, which directly prevents these postings from being recorded on the cost center.

Verification / Alternative check:
To verify the reasoning, imagine a cost center that should not receive further primary cost postings because it is being phased out. By setting the appropriate blocking indicator for primary costs, any new vendor invoices or primary postings to that cost center will be rejected or receive an error. However, internal allocations or certain commitments may still be processed depending on configuration. This scenario shows how primary costs can be explicitly blocked, confirming that this category matches the behavior described in the question.

Why Other Options Are Wrong:
Option A: Material withdrawals are one way of generating primary costs but they are not a separate blocking category. Blocking primary costs already covers these postings. Option C: Commitments are generally managed through budgeting and availability control, not via the cost center posting block indicator. Option D: Secondary costs in plan version alone are not the standard category for blocking; secondary postings are usually controlled through allocation cycles rather than a simple master data block.

Common Pitfalls:
Learners often confuse business processes, such as goods issues, with posting categories like primary and secondary costs. Another frequent mistake is to assume that commitments behave like actual costs with regard to posting blocks, even though they are managed through different mechanisms. Finally, some assume blocking a cost center means all postings are prevented, when in reality the configuration can be more granular, such as blocking only primary costs. Always classify postings by category before deciding what can be blocked on a cost center.

Final Answer:
The correct answer is Primary costs in actual and plan versions.