Choice "A" is correct. An auditor's analytical procedures are facilitated when an entity uses a standard cost system with variance reports because the comparison of actual to budget will already have been performed. In addition, it is likely that management will already be aware of significant variations from budget and will be better able to address any questions the auditor may have.
Choice "c" is incorrect. Segregation of obsolete inventory would not be an important factor in determining whether analytical procedures would be effective.
Choice "d" is incorrect. Correction of internal control weaknesses prior to the beginning of the audit would not affect analytical procedures.
Choice "b" is incorrect. Analytical procedures using data developed solely within the entity are not as reliable as analytical procedures using data developed externally.