Step 1: Mandarins have a rind that separates easily from the flesh, giving the name loose-skinned orange (Statement I, true).
Step 2: R.W. Hodgson's citrus classification recognised Satsuma, King and Willowleaf as principal mandarin groups (Statement II, true).
Step 3: Both facts are independently documented in citrus taxonomy.
Step 4: Both statements are true, so the answer is option (1).