(B) \( \left(\frac{5}{3}-0,7\right) \cdot 0,9 \)

To tackle this expression, let's start by converting \(0.7\) into a fraction for easier calculations. We know that \(0.7\) is equivalent to \(\frac{7}{10}\). Thus, rewriting the expression gives us \( \left(\frac{5}{3} - \frac{7}{10}\right) \cdot 0.9\). To perform the subtraction, we need a common denominator, which is \(30\). So, we can convert both fractions: \( \frac{5}{3} = \frac{50}{30} \) and \( \frac{7}{10} = \frac{21}{30} \). Therefore, the expression simplifies to \( \left(\frac{50}{30} - \frac{21}{30}\right) \cdot 0.9 = \frac{29}{30} \cdot 0.9 \). Finally, multiplying \( \frac{29}{30} \) by \(0.9\) (which is the same as \( \frac{9}{10}\)), we get \( \frac{29 \cdot 9}{30 \cdot 10} = \frac{261}{300} \), which can be simplified to \( \frac{87}{100} = 0.87 \). Thus, the final result is \(0.87\)!