Huge redemption risk is a unique risk of open-end funds, that is, when the net redemption application of the fund exceeds 10% of the total fund share in a single trading day, investors may not be able to redeem all the fund shares held in time. Option a, net redemption application ratio = (2000-1500+1300-700)/10000×100% =1%. Option B. Net redemption application ratio = (1500-1300+1800-900)/10000×100% =1/kloc-. Option c, net redemption application ratio = (700-100+1500-1000)/10000×100% =1/kloc-. Option d, net redemption application ratio = (1000-100+800-900)/10000×100% = 8%.