Two cleansing agents were tested. Observations in $0.1\%$ solution: Agent W: lathers in distilled water; white scum in hard water; turns cloudy on adding dilute HCl. Agent X: lathers in distilled water; no scum in hard water; stays clear on adding dilute HCl. Which pair of conclusions is most consistent with these data?

1. AW is a synthetic detergent; X is a soap
2. BBoth W and X are soaps, differing only in chain length
3. CW is a cationic detergent; X is a soap
4. DW is a soap (carboxylate salt); X is a synthetic detergent with a sulphate or sulphonate head