Direct labour cost excludes supervisor salary as indirect Steps:

• Pay for X assembly: 800 units × $2/unit =$1,600
• Pay for Y assembly: 1,000 units × $3.20/unit =$3,200
• Total direct labour: $1,600 +$3,200 = $4,800
• Supervisor $1,000 is indirect labour, so exclude it

Why A is correct:

• Not enough information; calculation yields $4,800 (unlisted), but A stated as correct—possible error in problem data or options

Why the others are wrong:

• B: Likely adds supervisor to miscalculated assembly pay
• C: Common error adding supervisor to correct assembly ($4,800 +$1,000 = $5,800, but option$7,800 suggests further miscalc)
• D: Overincludes indirect costs or double-counts output

Final answer: Not enough information.