Java reduce/collection, the many ways to skin a cat

reduce.java

// Option A
Integer totalFixedRateResultCount = fixedRateCounts
                                        .stream()
                                        .reduce(0, (aggValue, current) -> {
                                            Integer value = (Integer) current.getValue();
                                             return aggValue + value;
                                        }, (aLong1, aLong2) -> aLong1);

// Option B
Integer totalFixedRateResultCount = fixedRateCounts
                                          .stream()
                                          .reduce(0, (aggValue, current) -> {
                                              Integer value = (Integer) current.getValue();
                                               return aggValue + value;
                                          }, Integer::compareTo);

// Option C
Integer totalFixedRateResultCount = fixedRateCounts
                                        .stream()
                                        .map(entry -> (Integer) entry.getValue())
                                        .reduce(0, (aggValue, current) -> {
                                             return aggValue + current;
                                        }, Integer::compareTo);

// Option D
Integer totalFixedRateResultCount = fixedRateCounts
                                        .stream()
                                        .map(entry -> (Integer) entry.getValue())
                                        .mapToInt(Integer::intValue) // converts it to IntStream
                                        .sum();
// Option E
Integer totalFixedRateResultCount = fixedRateCounts
                                        .stream()
                                        .map(SimpleEntry::getValue)
                                        .map(Integer.class::cast)
                                        .mapToInt(Integer::intValue)
                                        .sum();

// Option F
Integer totalFixedRateResultCount = fixedRateCounts
                                        .stream()
                                        .map(SimpleEntry::getValue)
                                        .map(Integer.class::cast)
                                        .collect(Collectors.summingInt(Integer::intValue));