Current ratios and some related data for Apple Inc. in the last two fiscal years are as follows:$$

$20122013$Current Ratio$1\mathrm{.}501\mathrm{.}68$Net Sales $($$ millions$)156,508170,910$Cash & Equivalents $($$ millions$)10,74614,259$Short Term Marketable Securities $($$ millions$)18,38326,287$Accounts Receivable, net $($$ millions$)10,93013,102$Other Current Assets $($$ millions$)17,59419,638$Long Term Marketable Securities $($$ millions$)92,122106,215$Current Liabilities $($$ millions$)38,54243,658$Profit Margin $($$ millions$)26\mathrm{.}67\%21\mathrm{.}67\%$

What is the best explanation for the increase in the current ratio in $2013?$

Long term marketable securities increased significantly

Current liabilities increased by over $$5$ million.

Current assets continued to grow without a proportionate increase to its liabilities.