Global Realty Inc owned an office building. It leased the fourth floor to Jensen Corp for two years beginning 1 January 2013. Sarah Jensen, the president and sole shareholder of Jensen Corp, gave Global a personal guarantee of all of Jensen Corp’s obligations under the lease. By June 2013, Jensen Corp was having difficulty with its obligations and wanted to sublet part of the fourth floor. The lease permitted Jensen Corp to sublet so long as the landlord, Global, consented. The lease also provided that Global’s consent could not be unreasonably withheld. Jensen Corp found five different possible tenants, but Global would not consent to any of them. Global did not give any reason for its refusal. Eventually, Jensen Corp defaulted on its lease payments and Global demanded payment from Sarah Jensen under her guarantee. Is Sarah Jensen obliged to pay?