You have used fluorescence-activated cell sorting to separate blood T lymphocytes from a healthy person and a patient infected with a virus. To sort the cells, you used antibodies against two cell-surface receptors, CD4 and CD8, each conjugated to a different fluorescent dye. Based on the results below, which cell type do you think is depleted by the viral infection: CD4+ helper T cells (H) or CD8+ cytotoxic T cells (C)? In these dot plots, each cell is represented by a dot whose coordinates are the intensities of CD4 and CD8 signals. Write down H or C as your answer.