Explanation:

Equal-weighted indices have several disadvantages. One key disadvantage is that securities constituting the largest fraction of the target market value are underrepresented, while those constituting a smaller fraction are overrepresented. This occurs because equal weighting does not account for the relative market capitalization of the securities. Option B correctly identifies this disadvantage.

• Option A is incorrect because the issue is frequent rebalancing (not reconstitution) to maintain equal weights as prices change.
• Option C is incorrect because smaller stocks are overrepresented, not underrepresented, in an equal-weighted index.