Which terms could be used as the first term of the expression below to create a polynomial written in standard form? select five options. + 8r2s4 – 3r3s3 startfraction 5 s superscript 7 baseline over 6 endfraction s5 3r4s5 –r4s6 –6rs5 startfraction 4 r over s superscript 6 baseline endfraction.