Jeff's monthly utility and maintenance expenses are $308.38.
To calculate Jeff's monthly utility and maintenance expenses, we can use the given rates and his usage.
The calculation of Jeff's monthly utility and maintenance expenses:
Electricity: 250 kWh * $0.15/kWh = $37.50
Gas: 950 ft³ * $1/100 ft³ = $9.50
Gas (heating): 460 gallons * $0.03/gallon = $13.80
Phone: $40/month
Internet: $100/month
Maintenance: $120/month
Total utility and maintenance expenses: $37.50 + $9.50 + $13.80 + $40 + $100 + $120 = $320.80
Therefore, the answer is B. $308.38.