I put a plunger under sink and I have supplied a small spring type drain auger they are about $15 Usually first time I show them how to use it after that they are on their own (I will ask them if they are having anymore problems )

It also looks like the water valve has been turned 180 degrees up, that type of pump won't produce enough pressure to pump water up at the top of the stroke of the plunger.

At move in, all of my tenants receive a new sink and toilet plunger, snow shovels (usually still there from the last tenant), a sealing bucket from Home Depot that is full of snow salt (they get one free bag from me each year), and each stove has an oven liner to help keep the oven cleaner.

(if you are design-challenged, please have a woman/designer give you advise: it will pay long-term)--also make sure your house/units smell wonderific/seasonal (apple cinnamon/santal wood/ebony)-a welcome package would set you apart also (less then $10 at dollar tree supplies: toilet paper roll, cleaning paper roll, toilet plunger, cleaning brush, cheap shower liner, soap dispenser, all-purpose cleaner container, couple garbage bags) + box/pack of water bottles in the fridge-you do not need to buy stainless steel appliances, but do make connections with local used appliances store (they may have warranty in place, and know the appliances which make do /resists in the area). use white or black, simple and reliable type-find out which appliances tenants usually bring with them in the area-DO NOT implement the Section 8 Bible books advises (but do read the books).

Do you leave plungers in your rental units?  

A plunger or a 6' auger at standby.

Do you have a plunger ,  did you try to use it?

Never happened to me with 3 dozen units over 16 yrs)  is usually a simple fix anyway with a plunger or small snake. 

Yes, he’s licensed and insured.i did check with handyman he said I just used the plunger and cleaned the clogged.

If they want a plumber that bad they will have to pay $65 to have the plumber come out or they can do what most people do and get a plunger and do it themselves.