What did Richard Current mean when he described the Civil War after the summer of 1863 as a "war of attrition"? A. The South was unable to secure the support of foreign countries sympathetic to its cause after 1863. B. The North's superior resources and military strength would inevitably wear down the South's ability to continue the war. C. Southern generals remained able to engage Union forces without additional troops or supplies. D. Northern generals employed defensive strategies against which the Confederate forces stood little chance.