Savings positive when income exceeds total spending

Steps:

• Identify savings as income minus total household spending from the table.
• Compute savings for $3000: spending exceeds income, so negative.
• Compute savings for $3600: income now exceeds spending, so positive.
• Confirm higher incomes ($3900,$4200) also yield positive savings, but $3600 is lowest.

Why B is correct:

• At $3600, savings first become positive per the table's spending-income relationship.

Why the others are wrong:

• A: Savings negative at $3000 as spending > income.
• C: Not lowest; savings positive but $3600 is smaller.
• D: Not lowest; savings positive but $3600 is smaller.

Final answer: B