Josef is the sole owner of a property in Greenacre registered under the Real Property Act. Josef grants a mortgage to Mario. The mortgage is registered and Mario retains the Certificate of Title. Josef is also the registered proprietor of a property in Waterloo under the Real Property Act. Josef approaches Mario for another loan and offers the Waterloo property as security. Mario agrees. The next day Josef meets Mario and provides him with the signed mortgage dealing. The mortgage is then registered. Josef is unable to meet the mortgage repayments. Mario purports to exercise his power of sale under both mortgages. He advertises in the local paper and online. He also takes possession of both properties. Josef is not too pleased with Mario's decision to sell both properties immediately. He is concerned that the market is low and is convinced that both properties will fetch a better price in 6 months' time. Prior to the auction of the Greenacre property, Jim offers Mario $800,000.00 to buy the property. Mario rejects the offer and the property is sold at auction for $685,000.00

a. What rights does Josef have regarding the sale of the Greenacre property by Mario for less than the offer made by Jim?

b. Can Josef prevent the sale of the Waterloo property on the basis that the market may improve in 6 months' time?